Field of Invention
The present invention relates to a composition for film formation, a film, a production method of a patterned substrate, and a compound.
Description of the Related Art
In manufacturing semiconductor devices, multilayer resist processes have been employed for attaining a high degree of integration. In these processes, a composition for forming a resist underlayer film is first coated on a substrate to provide a resist underlayer film, and then a resist composition is coated on the resist underlayer film to provide a resist film. Then, a resist film is exposed through a mask pattern or the like, and developed with an appropriate developer solution to form a resist pattern. Subsequently, the resist underlayer film is dry-etched using the resist pattern as a mask, and the substrate is further dry-etched using the resultant resist underlayer film pattern as a mask, thereby enabling a desired pattern to be formed on the substrate. The resist underlayer film for use in such a multilayer resist process requires to have optical characteristics such as a favorable refractive index and extinction coefficient, and general characteristics such as etching resistance.
The multilayer resist processes involving a procedure of forming a hard mask as an intermediate layer on the resist underlayer film has been studied recently. Specifically, since an inorganic hard mask is formed on a resist underlayer film using CVD techniques according to this procedure, particularly in a case where a nitride inorganic hard mask is formed, the temperature is elevated to be as high as at least 300° C. and typically no less than 400° C., and thus, the resist underlayer film is required to have superior heat resistance. When the heat resistance is insufficient, a component in the resist underlayer film may be sublimated and the sublimated component may adhere to the substrate again, resulting in a disadvantage of a decrease in yields of the production of semiconductor devices.
Still further, patterns are more frequently formed recently on a substrate having a plurality of types of trenches, particularly trenches having aspect ratios that differ from each other, the resist underlayer film formed is desired to have these trenches sufficiently embedded thereinto, and also have superior flatness.
To meet these demands, structures of compounds, etc., to be contained in a composition have been extensively studied (see, Japanese Unexamined Patent Application, Publication No. 2012-214720, and PCT International Publication Nos. 2012/077640, 2011/021555 and 2010/055852). However, it has been still impossible to sufficiently meet the demands described above, according to the conventional compositions described above.